/Engine/Plugins/Runtime/GeometryProcessing/Source/DynamicMesh/Public/Operations/SmoothBoneWeights.h
Compute smoothed weights at a vertex and write the result into FDynamicMeshVertexSkinWeightsAttribute passed upon construction.
true if the algorithm succeeds, false if it failed or was canceled by the user.
bool SmoothWeightsAtVertex ( const int32 VertexID, const float VertexFalloff )